horrible customer service!!

Its been 2 years since we lodged our first complaint and still nothing! We bought a kia rio 1.2 specifically bec of the economical fuel consumption but omg! When a car thats meant to read 5.2/5.7L per 100 km reads 96.3L per 100km instead then clearly theres a problem! And then for a cheek they imply that i may have pressed the \ trip switch"?!no! I know my car! You have never ever responded! We have sent emails and even pictures of the crazy readings ive even done my own research and even let u know i was informed it sounds like the sender unit in the fuel tank that could be the problem.. Ive done half the job! Figuring out where to maybe look and now its ure turn to show up and fix it! What do u want me to do!? """